# Relationship history for MSHA mine 2900192

Current hierarchy: **Dickson A  Hilton III; John R  Funk → Santa Fe Mining Company → SANTO TOMAS**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **operator_operates_mine:** Big Chief Stone Inc → SANTO TOMAS; 1950-01-01 to 1997-12-07; source msha-controller-operator-history
- **controller_controls_mine:** Edna O  Morton  et al → SANTO TOMAS; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Edna O  Morton  et al → Big Chief Stone Inc; 1950-01-01 to 1997-12-07; source msha-controller-operator-history
- **controller_controls_operator:** Royce C  Morton  et al → Big Chief Stone Inc; 1950-01-01 to 1997-12-07; source msha-controller-operator-history
- **operator_operates_mine:** Santa Fe Mining Company → SANTO TOMAS; 1997-12-08 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** John R  Funk et al → SANTO TOMAS; 1997-12-08 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** John R  Funk et al → Santa Fe Mining Company; 1997-12-08 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Dickson A  Hilton III et al → Santa Fe Mining Company; 1997-12-08 to current/open; source msha-controller-operator-history